What this means
Redness shows that the skin is irritated or inflamed. It is easiest to see where the coat is thinner: the belly, armpits, groin, inside the ears and between the toes. On pale skin it shows easily, while on dark or pigmented skin you may only notice it because the dog is scratching or licking.
It is worth noting exactly where the skin is red. Redness in the armpits, groin, belly or between the toes, particularly with licking and scratching, raises the question of allergy or sensitive skin. Red areas around the eyes, on the muzzle or legs together with thinning hair may be linked to skin mites. Red, flaking skin can also simply mean sensitive skin.
Look at what the redness is like up close. Smooth, even redness is different from redness with pimples, crusts, dampness, smell or bald areas. Whether your dog is scratching, licking and chewing matters as well: scratching and licking irritate the skin themselves and make the redness worse.
Write down when the redness appeared, whether it comes back at the same time every year, whether it is spreading, and whether you have recently changed shampoo, food, bedding or cleaning products. These notes help your vet narrow down the possible causes sooner.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your dog.
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Allergy
Allergy to food, to things in the environment or to flea saliva causes itching and redness, especially on the belly, in the armpits and between the toes. The dog scratches, licks and chews.
About the condition: Allergies (food, skin and environmental) -
Atopic dermatitis
This is an allergic form of skin inflammation that tends to return. Redness is often seen between the toes, in the ears, around the eyes and on the belly.
About the condition: Atopic dermatitis -
Skin mites
Some mites settle in the hair follicles and cause red, flaking or bald patches. They may stay local or spread over the body.
About the condition: Demodectic mange -
Sensitive skin
Some dogs' skin is irritated by shampoo, grooming, bedding or water. It goes red and flaky, but there are no other signs of illness.
About the condition: Sensitive skin -
Bacterial or yeast infection
Infection often settles onto skin that is already irritated and deepens the redness. Pimples, dampness, crusts or smell may appear.
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Other skin diseases
Many skin diseases first show as red, flaking areas. What exactly you are seeing is decided by a vet after examining the skin and taking a sample.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- Where the redness is: belly, armpits, groin, between the toes, ears, muzzle
- Whether your dog is scratching, licking or chewing
- Whether there is also flaking, crusting, pimples or dampness
- Whether the coat in that area is thinning or has fallen out
- Whether the redness returns at the same time every year
- Whether you have recently changed shampoo, food or bedding
When to book a routine visit
Book a visit if the skin has been red for more than a few days, if the redness keeps returning or spreading, if there is itching, flaking, crusting or smell with it, or if the skin is keeping your dog unsettled.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Allergies (food, skin and environmental) Skin and coat An allergy is an overreaction of the immune system to substances that are essentially harmless, such as pollen, house dust mites, moulds, flea saliva or an ingredient in food. In dogs it shows up mainly in the skin and ears, and constant itching wears a dog down and can open the way to skin infections. More than one trigger can be involved at once, so finding the cause takes patience.
- Atopic dermatitis Skin and coat Atopic dermatitis is a long-term allergic skin disease driven by an inherited tendency: the skin overreacts to environmental allergens such as pollen, house dust mites or moulds. These dogs have a weaker skin barrier, so allergens get in more easily, and scratching irritates the skin even further. Signs can begin in young dogs and, depending on the allergen, may flare up at certain times of year.
- Demodectic mange Skin and coat Demodectic mange is a skin disease caused by microscopic Demodex mites that live in the hair follicles. A small number of them live on healthy dogs too, but when the immune system fails to keep them in check, the mites multiply rapidly and damage the skin and coat. It can stay small and local or spread over the whole body, which is a sign that the dog's body is struggling to cope.
- Sensitive skin Skin and coat Sensitive skin gets irritated easily: it turns red, itches or flakes, and skin folds that trap moisture can become inflamed. The irritation can come from a food or environmental allergy, parasites, unsuitable grooming products or other causes, and constant itching takes a real toll on a dog's comfort. What exactly is bothering a particular dog's skin is for a vet to work out.
- Skin problems Skin and coat This is an umbrella term for a range of skin disorders, from allergies and parasites to infections, hormonal diseases or growths in the skin. The skin also reflects a dog's overall health, so changes in it sometimes point to a problem elsewhere in the body, and constant itching or soreness takes a real toll on a dog's comfort. What lies behind particular changes is for a vet to work out.
- Fleas Parasites Fleas are small, jumping parasites that feed on a dog's blood and cause itching. Some of them live on the dog, while the eggs, larvae and pupae live in the home: in the dog's bed, carpets and soft furnishings. That is why fleas can keep coming back even when none are left to see on the dog; your vet can advise on protecting your dog and your home.
Body systems: Skin and coat Parasites